I have been exploring focus stacking. During my last trip to the US, I found a colony of Leucauge venusta - that weave more or less horizontal webs. In the early morning, with a low angle of the sun incident on the web, I sometimes saw in the camera image what appears sometimes there is what I called a diffraction pattern in a region of the image - similar to
Another example - illustrating a strand oriented at an angle to the focal plane.
Focus stacking requires that you take a series of images that are progressively further and further away from the focal plane. At the bottom of this page, you'll see a focus stack image of a funnel web spider. Fortunately, in reviewing the images, I saw that one strand to the left - was in focus and progressively turned into what I thought was a diffraction pattern. But perhaps its a Fourier Spectrum. Here is an animation of the sequence of images
Out of focus image
Animated gif of images passing from shallow focus to deep focus
In focus strand
A focus stack of a web that was bent at 90 degrees at the center - i.e. the region above the horizontal line through the center is horizontal and the region below a horizontal line through the center is hanging down- nice result - (using ZereneStacker)
A different algorithm, (using ZereneStacker)
Red dragon fly
An empty head
Yellow dragonfly
Mosaid of the compound eye (used to focus)
Skipper
Takeoff - wings before body
Hoverfly eating
Another view
Butterfly face
Planar wings
Fly with mosaic pattern of the compound eye
Facing me (curious guy)
Another view
Funnel web spider - focus stack to improve the depth of field
A different algorithm - you can clearly see the escape hatch behind her which is in the form of a cone or funnel
A different funnel web spider
Clearlly visible are all 8 eyes - 2 large and 4 small below oriented toward me and two upper eyes oriented perpendicular - pointing to either side. I how the spider processes this - perhaps to get a wide field of view - or does she simply switch from forward eyes to lateral eyes?
An "ordinary" image - shallow depth of field - A better view of the orientation of the 6 lower eyes and the two upper eyes
C. Frank Starmer